Online identification method and system of parameters of cell

Abstract

The invention provides an online identification method and system of parameters of a cell. The method and the system are applied to a cell device. The method comprises steps of establishing a cell equivalent circuit model including cell model parameters and constructing a relational expression meeting cell outer characteristic parameters of the cell equivalent circuit model; acquiring cell outer characteristic data; and according to the acquired cell outer characteristic data, by use of a preset algorithm, carrying out online identification on the cell model parameters in the relational expression of the cell outer characteristic parameters. According to the invention, the calculation complexity is quite low without storage and processing of massive history data; short time is spent without addition of additional devices; and cost is low.

Description

【Technical field】 [0001] The invention relates to the technical field of electric vehicles, in particular to a battery parameter online identification method and system. 【Background technique】 [0002] Pure electric vehicles are equipped with power battery packs, and battery state estimation is the core function of advanced battery management systems. At this stage, many battery state estimation algorithms need to use the battery circuit model. By establishing a battery model and inputting information such as voltage and current of the acquisition module, the estimation of the battery state is realized. Among them, the accuracy of the battery model parameters largely determines the accuracy of the algorithm. [0003] The battery model parameters mainly include battery open circuit voltage, battery ohmic internal resistance, battery polarization internal resistance, battery polarization capacitance, etc. How to accurately and effectively identify the above battery model par...

AI Technical Summary

Problems solved by technology

Another example is the measurement methods of battery internal resistance parameters in the prior art mainly include: DC discharge internal resistance measurement method, AC bridge method. Internal resistance

In addition, it is not possible to measure with external equipment during the driving of electric vehicles, so a method for online identification of equivalent resistance without adding test equipment is needed

[0004] The above-mentioned existing battery model parameter measurement methods mainly have the disadvantages of long time consumption, difficulty in online measurement and high cost of parameter acquisition.

For example, the measurement of the open circuit voltage requires the electric vehicle to stand still for several hours to accurately measure the open circuit voltage value, which is difficult to achieve for a driving electric vehicle

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